000
FXUS63 KAPX 181443
AFDAPX
Area Forecast Discussion
National Weather Service Gaylord MI
1043 AM EDT Sun Mar 18 2018
.UPDATE...
Issued at 1033 AM EDT Sun Mar 18 2018
Main thing for the afternoon is the cloud cover. With the high
pressure over the region, there is a war going on, with the dry
sfc flow and the dry mid to upper air versus the couple of thin
layers of moisture producing some cloud, in E Upper. The clouds
look to be aligned with sfc backdoor cold front sagging into the
forecast area. However, with the slow movement, and the drier air
surrounding these levels, think that with the sunshine we`ll see
mixing slowly erode most of the clouds during the day. Models are
suggesting that the clouds could reform around M-72 or M-55
overnight, and become overcast. Will look into this a little more
closely as the new 12z models come in for the afternoon forecast.
&&
.NEAR TERM...(Today through Tonight)
Issued at 205 AM EDT Sun Mar 18 2018
...Remarkably quiet weather to continue...
High impact weather potential: None.
Pattern synopsis/forecast: Moisture starved weak area of low
pressure dropping southeast across Lake Superior at this early
hour. Low itself running along quasi-stationary front layed out
near the St. Mary`s river, with this front aligned along rather
tight H8 thermal gradient (ranging from the negative mid teens
across Ontario, to the near zero across central Lake Michigan).
Extensive area of mid level clouds running on the colder side of
the thermal regime, with just a few wisps of cirrus to the south
of the surface front.
Surface features remain fairly progressive today, with that weak
area of low pressure dropping into New York state by later this
afternoon, with weak backside cold air advection propelling that
northern front through our area in the process.
Primary forecast concerns/challenges: Nothing significant. Of
course, will need to deal with temperature trends and the potential
for a bit of post-frontal low cloud development today.
Details: Quiet for sure. As mentioned, cold front expected to drop
south across the area this morning and early afternoon, perhaps not
clearing southern areas until later in the day as diurnal processes
interrupt its southern progress. Simply not enough forcing nor
moisture to kick off any precipitation. However, band of mid clouds
may clip eastern upper Michigan this morning, and post-frontal
cooler environment may support a bit of stratus/strato-cu across the
northern third of the area. Definitely not entirely sold on the
stratus idea given still robust dewpoint depressions. Will play it
conservatively for now, keeping skies partly cloudy. Developing cold
air advection not overly impressive, allowing strengthening mid-
March sun to at least partially work its magic. Will continue to
side with the warmer end of the statistical guidance spectrum, with
highs ranging from the middle 30s far north, to near 50 degrees down
near Saginaw Bay.
More of the same tonight as dry northeast flow develops on south
side of sprawling northern Ontario centered high pressure. May see a
bit of increasing high and mid level clouds overnight within
elevated fgen response. Will also need to watch for some potential
shallow Lake Huron induced clouds across northeast lower Michigan as
H8 temperatures drop into the negative lower teens. Extremely dry
low level environment may put the kibosh to any of that activity
however, as noted in some of the high res sounding guidance.
Maintenance of at least some surface wind should keep temperatures
from really tanking tonight. Still a seasonably chilly night, with
readings falling into the upper single digits and teens across
eastern upper and northeast lower Michigan.
&&
.SHORT TERM...(Monday through Tuesday)
Issued at 205 AM EDT Sun Mar 18 2018
...Cooler with a little more cloud cover...
High Impact Weather Potential...None
Pattern Synopsis/Forecast...Ridging at the surface and aloft will
continue to provide a quiet forecast for northern Michigan for the
first part of the work week. Weak cold advection will be ongoing
aloft, gradually advecting a drier airmass in from the north and
providing cool northeast flow near the surface through the period.
Primary Forecast Concerns...No significant forecast concerns with
ridging and a dry airmass allowing the stretch of benign weather
to continue. Main forecast issue is that the last few runs of the
GFS have been introducing some light, isolated precip (probably lake-
induced) down towards Saginaw Bay Monday and Tuesday mornings.
The GFS brings a tongue of colder 850mb air (around -13C) south
towards the Bay, which is a little farther south than the other
guidance. GFS forecast soundings also show a slightly deeper moist
layer just above the surface. Think the cold advection aloft will
definitely lead to steep low level lapse rates and some morning
stratocu across our south, which will diminish as daytime mixing
develops, then regenerate again Monday night. However, not sold on
the GFS` light precip chances at this time given the overall lack of
favorable moisture and some dryness in the lowest 0.5 to 1 km.
Suppose some virga would be plausible near Saginaw Bay, though.
Ongoing CAA and increased cloud cover will lead to cooler daytime
highs, ranging from the mid 20s north to mid/upper 30s south on
Monday...and a degree or two colder on Tuesday.
.LONG TERM...(Tuesday night through Saturday)
Issued at 205 AM EDT Sun Mar 18 2018
High Impact Weather Potential...None.
Quiet weather continues right on into the middle of the week as
strong surface high pressure over Canada continues to extend into
northern Michigan. Weak ridging aloft Tuesday night will give way to
a weak shortwave crossing northern Michigan Wednesday into Thursday.
The low levels should remain sufficiently dry to prevent any
precipitation, however, so for now expecting only an increase in
clouds with this feature. However, the GFS wants to spit out some
light precip near Saginaw Bay once again Wednesday morning.
Additional ridging at the surface and aloft moves across northern
Michigan Thursday night into Friday. The next potential for light
precipitation (across our southern counties anyway) looks to come
Saturday as a strong surface low races through the Ohio Valley and
interacts with a baroclinic zone stretching back into the Northern
Plains. The GFS, ECMWF, and CMC all show this general idea to some
extent. At this time it looks like the best moisture and dynamics
will stay just south of our area, but that will depend on how far
south the surface low tracks and exactly where the baroclinic zone
sets up.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 638 AM EDT Sun Mar 18 2018
Mainly VFR conditions expected through the forecast period. A
weak area of low pressure will continue to move southeast away
from the region this morning. In its wake, shallow cold advection
could bring some sct-bkn MVFR stratus/strato-cu over northern
parts of the forecast area (KAPN and KPLN) later this morning and
early afternoon. Confidence in this occurring remains very low.
Any low clouds should for the most part mix out during the
afternoon hours. A few passing high clouds tonight, although some
potential for a scattered lake induced strato-cu deck to impact
KAPN overnight. Will continue to monitor. Winds will remain
generally light through the duration.
&&
.MARINE...
Issued at 205 AM EDT Sun Mar 18 2018
Yes...the nearshore season has begun (although the SOO
locks do not open until March 25th). And, a definitely quiet
start to the season as both winds and waves look to remain below
advisory criteria. Winds are expected to get a bit gusty over the
big waters later this morning and afternoon as they swing around
to northerly behind a passing cold front. Winds will slowly veer
to a more northeast direction tonight, with northeast winds, at
times a bit gusty, continuing right through Monday and Tuesday.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
&&
$$
UPDATE...JL
NEAR TERM...MB
SHORT TERM...MK
LONG TERM...MK
AVIATION...MB
MARINE...MB